Update rmqamqpt_frame.cpp

Signed-off-by: Evgeny Malygin <[email protected]>

src/rmq/rmqamqpt/rmqamqpt_frame.cpp

@@ -66,19 +66,21 @@ Frame::ReturnCode Frame::decode(Frame* frame,
  return Frame::PARTIAL;
  }
 
- bsl::memcpy(&frame->d_type, &buffer[0], sizeof(frame->d_type));
-
- bdlb::BigEndianUint16 channel;
- bsl::memcpy(&channel, &buffer[1], sizeof(channel));
- frame->d_channel = channel;
-
+ // Decode payload length first to return early if Frame is not full.
  bdlb::BigEndianUint32 payloadLength;
  bsl::memcpy(&payloadLength, &buffer[3], sizeof(payloadLength));
 
- if ((frameOverhead() + payloadLength) > bufferLen) {
+ if (bufferLen < (frameOverhead() + payloadLength)) {
  return Frame::PARTIAL;
  }
 
+ // Finally decode the skipped parts of the header.
+ bsl::memcpy(&frame->d_type, &buffer[0], sizeof(frame->d_type));
+
+ bdlb::BigEndianUint16 channel;
+ bsl::memcpy(&channel, &buffer[1], sizeof(channel));
+ frame->d_channel = channel;
+
  bsl::size_t buffer_len = frameHeaderSize() + payloadLength;
  if (buffer[buffer_len] != Constants::FRAME_END) {
  BALL_LOG_ERROR << "Decode error: expected Frame End marker. Frame: "